In the related art, an electronic photography type image processing device implementing the Carlson process is known. In this image forming device, in general, a photoconductive photoreceptor is uniformly charged; a latent image is produced as a charge distribution by an image exposure that depends on an image pattern; and the latent image on the photoreceptor is manifested with a toner, which is a resin colored fine particle charged positive or negative. Thereafter, the toner image on the photoreceptor is transferred onto a surface of a transfer material such as a transfer paper by an electrostatic force, the toner image is fixed onto the transfer material using an elasticity of the toner by passing it through rollers to which pressure is applied, making it possible to obtain a final toner image. It is common to use thermal energy for a toner fixing unit which uses the elasticity of the toner to fix the toner.
In the toner fixing unit which uses the thermal energy, the toner image on the transfer material and a surface of a fixing member which includes a heated roller, etc., may come into direct contact, possibly causing an offset phenomenon such that a part of the toner image adheres to the surface of the fixing member or a winding phenomenon such that the transfer material winds itself at the transfer material. A method is known that, in order to prevent the above-described winding phenomenon of the transfer material and the offset phenomenon, a mold release layer of Teflon (a registered trademark) or of silicone is provided on the surface of the fixing member, and oil as the mold release layer (for example, Silicone oil) is applied to the surface of the fixing member (See Non-patent document 1, for example). Moreover, a method is known that, a toner to which a wax as a mold release agent is added is used to form an image in order to be able to decrease the amount of oil applied to the surface of the fixing member or to do away with the oil application itself (see Non-patent documents 1-4).
In recent years, improvements in the speed and the quality of the above-described image forming devices using the electronic photography method have been advancing, and peripheral devices which process paper are also being enhanced. Moreover, for the image forming devices using the electronic photography method, it is not necessary to make a die plate. For these reasons, the image forming device using the electronic photography method is starting to be used in an area in which a related art printing machine such as an offset, etc., is being used as a print on demand (below called “POD”) unit. For use as such a POD unit, in order to provide added value by post processing to a transfer material as a printed matter, a coating processing such that varnish is applied to the fixed surface of the transfer material or a coating processing of film, etc., which is represented by PP (polypropylene) laminating, may be carried out. By such a processing of coating the film or the varnish, added value may be obtained such as a prevention of rubbing or cracking, or a sense of quality due to a highly gloss finish. However, when the processing of coating the varnish or film is carried out on a fixed transfer material output from the image forming device using the above-described electronic photography method (the POD unit), oil or wax for obtaining the above-mentioned mold releasability may have an effect on unevenness of the varnish applied onto the transfer material and adhesiveness between the transfer material and the film. In other words, the oil or the wax as the mold release agent exists on the fixed surface of the transfer material, so that a phenomenon may occur such that an adhesive of the varnish or the film is repelled and the varnish cannot be applied uniformly, or that a certain level of adhesiveness cannot be obtained between the transfer material and the film.
In order to avoid such a phenomenon as described above, it is possible that the transfer material is left as it is until the oil which exists on the surface of the transfer material decreases due to immersion, etc., or alternatively, a special adhesive or varnish to which a surfactant or alcohol is added is used. However, an inefficient operation such as leaving the transfer material as it is could lead to a drop in operational efficiency, and the use of the special varnish or adhesive could lead to an increased cost.
Moreover, there is also a problem that, when there exists oil or wax as the mold release agent on the fixed surface of the transfer material output from the image forming device using the electronic photography method as described above, it is difficult to seal on or add with writing instruments onto the fixed surface of the transfer material, so that it is not possible to obtain satisfactory correctivity.
Patent Documents
Patent document 1: JP62-100775A
Patent document 2: JP3-91764A
Patent document 3: JP3-168649A
Patent document 4: JP8-334919A
Non-Patent Document
Non-patent document Institute of Electronic Photography, “Basics and Applications of Electronic Photography Techniques”, First Edition, Corona Publishing, Jun. 15, 1988, pp. 321-324.